Weight Loss After Bariatric Surgery - What Is Normal?

So you’ve had bariatric surgery and your weight has started to decrease – fabulous! But there are no doubt some questions on your mind:

• How much weight should I be losing and what is “normal”
• Why does my weight vary so much from day to day?
• I know I have lost weight, but how come I just don’t feel like I’ve lost all that much?

These are all great questions and you will probably be driving yourself nuts trying to find the answer. So I’m going to clarify these for you a bit – well, sort of. You see, there is no “normal” and there is no standard set of outcomes that we can expect for everyone. We are all very different. From our genetic make-up, life experiences, environment, right down to our personalities – we are all unique individuals and hence there is no magic formula that will tell us exact answers to these questions. I can however, give you a rough guide as to what to expect post bariatric surgery from a weight perspective and this will hopefully help you to set some realistic health goals.

1. So how much weight should I lose and at what rate?

Firstly, there are many types of bariatric surgery and your weight loss trajectory will vary depending on the type of surgery you have had. Weight loss following a lap band is typically very gradual compared to weight loss following a sleeve gastrectomy or gastric bypass. Having said that, those that have had revisional bariatric surgery (eg. gastric bypass after having had a lap band) will tend to lose weight at a slower rate than those having a gastric bypass as a primary procedure. The total amount of weight lost is also variable and is generally more with a gastric bypass or sleeve gastrectomy compared to a lap band or intra-gastric balloon. Even though this is both confusing and at times frustrating, the point I want to emphasise is that it doesn’t really matter how much weight you lose or how quickly you lose it. Everybody’s weight loss journey is unique and individual. There is no right or wrong. What matters most is that you don’t compare yourself to others and that you focus on your own journey.

2. So you’ve jumped on the scales this morning and you are 800g heavier than yesterday.

Now let me guess – you immediately think, how the hell can that have happened? What did I eat yesterday? And what am I doing wrong? My first tip for you is to either throw your scales away or put them up in the cupboard so you can’t weight yourself every day. Weighing every day can be confusing and is certainly not necessary. The only thing it does do is make you anxious! Day to day variation in weight is completely normal. If you have just eaten, had a glass of water, not had a bowel motion for a day or so or are pre-menstrual then you are likely to weigh more. These small fluctuations balance out over time. If you are only weighing every 1-2 weeks then the likely hood is that you will see the numbers continually go down and will save yourself the heartache of seeing all the little “ups and down’s” in between.

3. So now you’re getting a lot of positive comments about your weight – “gee – look at you – you look amazing – well done!”.

You may hear this quite a bit following your bariatric surgery. So why doesn’t it always feel right? Why is it that you can look in the mirror every morning and know you have lost a heap of weight, but not actually “see” it or feel like you have. This altered sense of body image can be very normal and sometimes confronting. Reality is that you are seeing yourself day to day and may not really realise how much weight you have lost. Your brain is used to seeing a certain shape and can sometime take a while to catch up. Rest assured that this is very common and usually doesn’t last that long. If you have significant concerns about it though – it is best to talk with your bariatric clinic about these feelings.

4. Ok, so why has the number on the scales not moved for weeks and yet I’ve had to pull my belt in a notch?

You may think that your mind is playing tricks on you or that you are going a little crazy, but this phenomenon can be completely normal and occurs more frequently than not following bariatric surgery. The reason is, that our body composition changes. We may have gained some muscle and lost some fat. Because muscle weighs more than fat, then the actual weight can stay the same and yet our fat stores in certain areas has actually gone down. We also get what is called fat re-distribution – fat can move from certain places to others and this can also cause a change in body shape. But don’t worry – this is very normal and it’s probably best just not to think too much about it!

So by now you have hopefully realised that there is no “normal” when we talk about weight loss post bariatric surgery. I can’t emphasise enough that your journey is your journey and your body is working very hard. It does a tremendous job in the early months following surgery and your weight loss trajectory is very individual and unique. So don’t compare yourself to others. Just know that the human body is truly remarkable and it will do what it thinks it should. Don’t get me wrong, there are certainly ways we can manipulate your weight loss to some degree, but in the early months just be kind to yourself and go along for the ride! Just remember that if you are ever concerned in any way, your bariatric clinic is the best source of information and should be contacted when required.

Dr Zanna Murfitt,
(General Practitioner with a special interest in bariatric medicine)